Renewable energy sources are a substitute for fossil fuels and provide a means of reducing dependence on petroleum oil. Biomass is conventionally used as a feedstock to produce renewable energy sources, such as biofuels.
Catalytic thermolysis processes such as pyrolysis have been developed that use biomass as a feedstock to produce useful biofuels. Such processes produce liquid products that spontaneously separate into an aqueous phase and an organic phase. The organic phase is commonly referred to as bio-oil. While thermolysis processes produce high yields of bio-oil, most, if not all, of the bio-oil produced is of low quality due to the high amount of oxygen present in the bio-oil.
Bio-oil can be stabilized and converted to a conventional hydrocarbon fluid by removing the oxygen through hydrotreating. This process involves contacting the bio-oil with hydrogen under pressure and at moderate temperatures, generally less than 750° F., over fixed bed reactors. Hydrotreating the bio-oil makes it compatible with petroleum derived refinery streams.
However, when bio-oil containing streams are hydrotreated, heavy components in the bio-oil can render coke forming heavy materials and solids which can plug the catalytic hydrotreating bed and reduce on-stream time.
A system is therefore needed that can remove such undesirable components from the bio-oil in order to improve the hydrotreating process and render quality products.